Ventilating system for subways

ABSTRACT

In a subway ventilating system where two stations are connected by a pair of tunnel tubes, a cross-connection is provided between the tubes adjacent each of the stations. The cross-connections are not open to the outside atmosphere. Fans are located in the cross-connections for withdrawing a fractional amount of the air pushed ahead of the train as it moves through one of the tubes and for injecting it through a nozzle into the other tube in the direction toward the station from which the train departed. Due to the injection of a portion of the air into the other tube, the remaining portion of the air pushed ahead of the train is pulled into the other tube and is directed back toward the station from which the train departed. Further, for ventilating the tunnel tube and the station, a ventilating shaft is located in a midportion of the tubes intermediate the stations for withdrawing air from the tubes and directing it into the outside atmosphere and for pulling air in from the outside atmosphere and circulating it into the tubes.

. United States Patent 11 1 Swaty VENTILATING SYSTEM FOR SUBWAYS [75] Inventor: Franz Swaty, Wien, Austria [73] Assignee: Stadt Wien, Vienna, Austria [22] Filed: Sept. 13, 1972 [2]] Appl. No.: 288,697

[30] Foreign Application Priority Data Sept. 16, 1971 Austria 8058/71 [52] US. Cl. 98/49 [51] Int. Cl. E0'1g 7/02 [58] Field of Search 48/49 [56] References Cited I UNITED STATES PATENTS 136,563 3/1873 Vandenburgh 98/49 855,118 3/1907 Morris 98/49 917,653 4/1909 Phelps.. 98/49 1,185.453 5/1916 Walker.... 98/49 Primary Examiner-William F. ODea Assistant Examiner-Peter D. Ferguson Attorney, Agent, or FirmToren, McGeady & Stanger 1111 3,823,654 July 16, 1974 [5 7] ABSTRACT In a subway ventilating system where two stations are connected by a pair of tunnel tubes, a crossconnection is provided between the tubes adjacent each of the stations. The cross-connections are not open to the outside atmosphere. Fans are located in the cross-connections for withdrawing a fractional amount of the air pushed ahead of the train as it moves through one of the tubes and for injecting it through a nozzle into the other tube in the direction toward the station from which the train departed. Due

to the injection of a portion of the air into the other tube, the remaining portion of the air pushed ahead of the train is pulled into the other tube and is directed back toward the station from which the train departed. Further, for ventilating the tunnel tube and the station, a ventilating shaft is located in a' mid-portion of the tubes intermediate the stations for withdrawing air from the tubes and directing it into the outside atmosphere and for pulling air in from the outside atmosphere and circulating it into the tubes.

17 Claims, 4 Drawing Figures PATENTEDJUL 1 61974 SBEEIIBEZ FIG.E

Mu" A 1. VENTILAT ING SYSTEM FOR SUBWAYS SUMMARY, OF THE INVENTION The present invention is directed to a ventilating system for subways and, more particularly, it concerns an arrangement for ventilating two-one way tunnel-tube extending between a pair of stations.

In subways where a separate tunnel tube is provided for each direction of travel of a train between stations, a problem has been experienced in protecting the station platforms from the air stream which is pushed ahead of a train as it moves from one station to another. The air forced ahead by the train leaves the tunnel tube at a high speed, it causes discomfiture to persons waiting on the platform and is bothersome on staircases and escalators leading to the platform. Further, it has been found that in many existing subways, the flow of air driven ahead of a train does not provide a suitable change of air in the stations. But a change of air contributes essentially to the comfort of the passengers,

since especially during rush hours the oxygen consumption of the passengers is high and the odor level in the tunnel is considerable, especially in rainy weather due to wet clothing.

Until the present time it has been attempted to solve this problem by positioning, adjacent each end of the stations, a ventilating shaft for each tunnel tube so that air pushed ahead of a train is vented into the outside atmosphere before it reaches the station. Further, such shafts also afford a passage of air into a tunnel tube as a train leaves the station and passes into the tube toward the next station. These ventilating structures, referred toas surge shafts, have been unable to solve the problem. A particular disadvantage of these structures is the uncontrollable amount of air which they introduce into the tunnel tubes. When the temperature of the outside atmosphere is low, ice has had a tendency to form in the tubes, while in the summer months the air temperature within the tubes becomes unbearable. To avoid the unpleasant air currentsalong the platform, caused by approaching and departing trains, these known ventilation structures have been provided in the immediate vicinity of the stations. The optimum distance of the ventilating shafts from the stations has been assumed to be 5 to diameters of the tunnel tube if the area ratio of the ventilating shaft cross section to the tunnel tube cross section is about 0.6.

Therefore, it appears that these shafts should be arranged approximately to 50 m from the opposite ends of each station. Often it is not possible to locate the ventilating shafts at the optimum distance when the stations are located in a congested area of a city. Usually, the requisite space for such a ventilating shaft is not available at the proper distance from the station. As a result, if the shaft cannot be located at the'optimum distance, the efficiency of the ventilating action is greatly decreased.

Based on this known, ventilating system, for each pair of tunnel tubes extending between two stations there must be four ventilatingshafts and such an arrangement is costly.

Another disadvantage of this known ventilating system is that these surge shafts have a very limited effect on the blast of air driven-into a station by an approaching train, and, due to this, the results obtained from such shafts are usually just barely acceptable but are station and on the temperature of the outside atmosphere. In winter, the flow of cold air into the subway is too great, and in the summer when the temperature of the outside atmosphere is'high, the effect of daytime ventilation due to train traffic results in a worsening of as it moves into a station is withdrawn from the station by another train leaving in the opposite direction. This type'of flow is particularly noticeable when the passage of air occurs in an enlarged approach area of the station, that is, in advance of the platform. Such an approach area can be provided, for example, by replacing the walls separating the tunnel tubes with a row of columns. In such an arrangement of the tunnel tubeapproach area-tunnel tube-approach area, neither the platform nor its entrances or exits would be pressurized by the passage of air and an ideal state offlow would be obtained.

However, if a train runs in only one of the two tubes between adjacent stations, such circular flow of the air will not take place. Tests in existing subway systems have shown that only about 22 percent of the air pushed ahead of the train follows the above-described circulation pattern. instead, about 37 percent of the air flows into the outside atmosphere through the surge shaft, and about4l percent flows out through the station entrances and exits. A similar air flow pattern occurs in the station from which the traindeparts. About 22 percent of theintake air is supplied from the air circulating system, .48 percent flows in through the surge chambers and 30 percent flows'from the outside atmosphere through the station intothe tunnel tube.

In accordance with the present invention, the basic concept is to maintain an optimum air circulation when a train is passing through only one of the tunnel tubes between two stations. This effect is achieved by installing fans between adjacent stations so that in the tube in which a train does not pass, the air flow corresponds approximately to that which occurs when a train moves through that tube. :ln effect, the flow of air through the tubes is maintained the same as if a train was passing through each of the tubes. If, during a particular period, no trains are running between adjacent stations, the flow through the tubes can be maintained by fans, but with a smaller flow of air. When a train enters one of the tubes, the full flow quantity required can be attained in 'a few seconds by speed variation of the fans.

The fans are installed in galleries or crossconnections which interconnect the two tubes immediately adjacent the end of the station. If the crossand inject it into the other tube for flow in the opposite BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIGS. 1 to 3 are schematic illustrations of the passage of air in two tunnel tubes between adjacent stations, with FIG. 1 exhibiting a known ventilation system and FIGS. 2 and 3 showing the ventilating system in accordance with the present invention; and

FIG. 4 is a transverse sectional view taken along line IVIV in FIG. 3 showing the tunnel tubes and a ventilating shaft.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 two adjacentsubway stations 1,2 are connected by a pair of tunnel tubes 3,8 and a train 4 is shown travelling from station 1 to station 2 through tube 3. Tunnel tube 8 is intended for the passage of a train in the opposite direction, that is from station 2 to station l.-At each end of tunnel tubes 3 and 8 a surge shafts, l1 and 7, 9 is provided, respectively, and, in addition, the station 2 has entrances and exits 6 while station 1 has entrances and exits 10. When the train 4 passes through tunnel tube 3 from station 1 to station .2, note the arrow, it pushes a quantity of air ahead'of it which,.at a tunnel cross-section of 20 m anda running speed of 17 m/s, is about 140 m /s. Of this quantity of air forced by the train toward station 2, 38.2 m /s are discharged into the outside atmosphere through the surge shaft 5, 56.6 m /s flows through the entrances and exits 6 of the station 2 and 20.4 m /s exits through the surge shaft 7 which is located in the tunnel tube 8 adjacent the station 2. Further, 30.3 m /s flow through the tunnel tube 8 from station 2 to station 1 and, in station 1, are drawn into the end of tunnel tube 3. Due to the suction effect of the train 4 moving from station 1 to station 2, 14.1 m /s of air are drawn in through the surge chamber 9 in tunnel tube 8 adjacent station 1',

' 42.7 m /s enter through the entrances and exits 10 of In FIGS. 2 and 3 the same reference numerals are used as in FIG. 1 to designate the same elements. In

FIG. 2 a gallery or cross-connection 12, 14 is shown extending between the tunnel tubes 3 and 8 adjacent the ends of the tunnel tubes at the platforms 1,2. In crossconnection 12 three axial fans 13 are positioned, only one is shown schematically in the drawings, and the fans have a total delivery of 28 m /s. Similarly, in the cross-connection 14, adjacent platform 2, three axial fans 15 are provided which provide the same air flow or output as the fans 13. When the arrangement shown in FIG. 2 is used, the following flow pattern results.

when the train 4 travels through the tube 3 from station 1 to station 2 and displaces m /s of air, if the dimensions of the tunnel tube and the velocity of the train are the same as stated in connection with FIG. 1. Of the total air flow forced ahead by the train 4, 28 m /s of air are drawn through the cross-connection 14 by the fans 15 and are injected into tube 8 by means of the injection nozzles 16 opening into tube 8. The flow from the injection nozzles is in the opposite direction to the direction of travel of the train 4 to the tube 3. At an injection ratio of 1:4, the quantity of airinjected into the tunnel tube 8 through the nozzles 16 draws 112 m /s' plied into the end portion of the station from the tube 3 as the train 4 moves toward the station 2. Therefore,

as can be noted in FIG. 2, the flow from tube 3 passes into the adjacent end of tube 8 for flow back toward station 1. r

Similarly, the flow at the'opposite ends of tubes 3 and 8 is the same with the major portion of the air passing through the end portion of the station adjacent the ends of the tubes. As a result, a closed flow circuit is provided and there is no flow of air into or out of the sta tions through their exits'and entrances.

When a train enters tube 8 moving from station 2 to station 1, there is no change in the circulation of air and the power expenditure for the fans would be practically zero. When the train 4 leaves tube 3, it is desirable to reduce the quantity of air circulating through the tubes and this is done byreducing the speed of the fans. As soon as a train enters one of the tubes 3,8, the fans are brought to full power within a few' seconds.

As indicated by FIG. 3, in this novel ventilating system, it is unnecessary to use the surge chambers employed in the prior art. However, even without the surge chambers there is no air blast in the stations or through their entrances and exits.

If, however, air is to be introduced into the tunnel tubes from the outside atmosphere or if the temperature of the circulating air is to be regulated, it is sufficient to locate a ventilating shaft 17 intermediate the stations 1, 2, as indicated in FIG. 3. The ventilating shaft 17 consists of four channels 18, 19, 20 and 21, two of which communicate with the tunnel tube 3 and the other two which communicate with the tunnel tube 8 through connecting passages. In the channels or in the connections to the tunnel tubes, fans are provided for withdrawing or supplying about one fourth of the circulating air quantity in a given period of time. The actual amount of air charged into the tunnel tubes is controlled in accordance with the oxygen requirement and also with the temperature of the outside atmosphere. Thus, in winter it is readily possible to maintain a temperature of approximately 20 C in the tubes, while on hot summer days the circulation of air through the tunnel tubes is effected only during the evening, night and early morning hours for lowering the temperature in the tunnel tubes.

In FIG. 4, the ventilation shaft 17 located intermediate the ends of the tubes 3 and 8, as shown in FIG. 3,

is indicated in transverse section with an air inlet channel 18 connected to the tube 3 and an exhaust air channel 19 connected to the tube 8. Similarly, a fresh air channel 20 is provided for the tube 8 and a exhaust channel 21 is provided for the tube 3. The ventilating shaft 17 is shown extending above the ground surface with a filter 21 at its upper end and a sound damper 22 located adjacent the filter. At the lower end of the channel 18 it is connected to the tube 3 by a gallery 23. A fan 20 is located within the gallery 23 for drawing in fresh air from the outside atmosphere and directing it into the tunnel tube 3. In the exhaust channel 19, a fan 24 is provided in the vertical portion of the channel for exhausting air from the tube 8 through the gallery 25 and discharging it through a sound damper 26 in the upper end of the channel. Positioned within the lower end of the ventilation shaft 17 is a register 27' positioned in both of the channels 18 and 19 so that the communication between the tunnel tubes and the outside atmosphere can be closed by the register 27 which can be lifted and lowered within the shaft, note the full line and dashed line showing in FIG. 4.

The present invention provides a number of advantages over the prior art. Initially, instead of four surge shafts each located ina tunnel tube adjacent the station, only one ventilation shaft is required which has a cross-section approximately the same as one surge chamber. The ventilation shaft or tower can be built in thecentral portion of the tunnel tubes between the stations, rather than at the ends of the tunnel tube adjacent the station. The zone of the tunnel tubes suitable for the ventilation tower is located in approximately the middle 70 percent of the length of the tubes between the stations. With this arrangement it is possible to locate the ventilation tower in a position which is most advantageous both with regard to city planning and cost.

By the new ventilation system the movement of air at theplatform level of the stations and particularly through the entrances and exits to the stations, is reducedto an imperceptibly small amount.

The introduction of outside air into the tunnel tubes can be controlled in accordance with the oxygen requirement or in accordance with the temperature requirements to be maintained and, further, it is possible to ensure optimum values within the tunnel during each season of the year. Air filters can be provided in the ventilation towers which avoid fouling of the tunnel tubes and the stations by soot and dust.

The power cost for the air movement through the tunnel tubes is between 1 and 2% of the power cost for running'the trains, a portion of this cost is offset by the lower air resistance of the train.

The ventilating system, in accordance with the pres ent invention, provides satisfactory conditions for the air within the tunnel tubes so that the tunnel air can be used for ventilating the subway cars.

What is claimed is: I

I 1. In a subway system having two one-way tunnel tubes extending between adjacent stations, the method of ventilating the tunnel tubes comprising the steps of providing cross-connections between the two tunnel tubes at locations adjacent to each station, as a train travels in one direction through one of the tunnel tubes withdrawing a portion of the air pushed ahead of the train in the one of the tunnel tubes at the crossconnection which the train is approaching and directing the withdrawn air into the other tube for flow in the opposite direction, and at the cross-connection at the end of the tunnel tubes adjacent the station from which the train is proceeding, withdrawing air from the other tube and directing it into the one of the tunnel tubes for flow in the direction in which the train is travelling.

2. In a subway system, as set forth in claim 1, including withdrawing one-fifth of the air from the one of the tunnel tubes and injecting it into the other one of the tunnel tubes for redirecting the remainder of the air flowing through the one of the tunnel tubes as it exits from the one of the tubes into the other one of the tubes.

3. In a subway system, as set forth in claim 1, including controllably admitting the air from the one of the tubes in front of the train into the cross-connection.

4. In a subway system, as set forth in claim 3, characterized therein by controlling the flow of the air from the one of the tunnel tubes into the other one of the tunnel tubes by variably regulating the amount of air withdrawn from the one of the tunnel tubes.

5. In a subway system, as set forth in claim 1, including ventilating the tunnel tubes at a location intermediate the cross-connections by withdrawing air fromthe tubes and supplying fresh air from the outside atmosphere into the tunnel tubes.

6. In a subway system, as set forth in claim 5, wherein the ventilating of the air in the tunnel tubes is effected by renewing 40 percent of the air.

7. In a subway system having two one-way tunnel tubes extending between adjacent stations, wherein the improvement comprises a ventilating system comprising means forming at least one cross-connection between the tunnel tubes at locations adjacent each of the stations, and means located in said cross-connections for withdrawing air from one of the tunnel tubes and directing it into the other one of the tunnel tubes so that the circulation of air can be effected in a closed circuit through the tunnel tubes and the .crossconnections whereby the circulating flow of air to the tunnel tubes and the cross-connectionsavoid drawing air in from the outside atmosphere and causing the'flow of air to the stations and through the entrances and 1 means for ventilating the tunnel tubes are located intermediate the cross-connections adjacent the stations and are connected to the outside atmosphere for ex hausting air from and supplying fresh air to the tunnel tubes.

9. In a subway system, as set forth in claim 8, wherein said means for ventilating the tunnel tubes includes fans for withdrawing air fromthe tunnel tubes and fans for supplying air into the tunnel tubes.

10. In a subway system, as set forth in claim 9, wherein said means for ventilating the tunnel tubes includes walls forming a ventilation shaft extending between said tunnel tubes and the outside atmosphere, partitions dividing said shaft into a pair of flow passageways'for each of said tunnel tubes, each of said flow passageways containing one of said fans so that for each pair of said flow passageways one flow passageway supplies air into one of the tunnel tubes and the other withdraws air from the one of the tunnel tubes.

11. In a subway system, as set forth in claim 10, wherein said ventilating shaft is located in a middle section of said tunnel tubes between the opposite ends thereof.

12. In a subway system, as set forth in claim 10, wherein said ventilating shaft is located in the zone intermediate the ends of said tunnel tubes representing 70 percent of the length between the ends of said tunnel tubes.

13. Ina subway system, as set forth in claim 10, wherein said ventilating shaft includes filters for the air being circulated therethrough,sound dampers located in the upper portion of said flow passageways of said shaft, and openable and closeable register members located in said flow passageways for regulating the flow of air into and out of said tunnel tubes.

14. In a subway system, as set forth in claim 7, wherein said means forming cross-connections comprises at least one conduit forming member extending between the tunnel tubes.

15. In a subway system, as set forth in claim 14,

wherein said conduit forming member includes an in-v jection nozzle for injecting air into the other one of the 17. In a subway system, as set forth in claim 16,

wherein said fans are variably operable for regulating the flow of air withdrawn from the one of the tunnel tubes and for supplying the air into the other one of the tubes. 

1. In a subway system having two one-way tunnel tubes extending between adjacent stations, the method of ventilating the tunnel tubes comprising the steps of providing cross-connections between the two tunnel tubes at locations adjacent to each station, as a train travels in one direction through one of the tunnel tubes withdrawing a portion of the air pushed ahead of the train in the one of the tunnel tubes at the cross-connection which the train is approaching and directing the withdrawn air into the other tube for flow in the opposite direction, and at the crossconnection at the end of the tunnel tubes adjacent the station from which the train is proceeding, withdrawing air from the other tube and directing it into the one of the tunnel tubes for flow in the direction in which the train is travelling.
 2. In a subway system, as set forth in claim 1, including withdrawing one-fifth of the air from the one of the tunnel tubes and injecting it into the other one of the tunnel tubes for redirecting the remainder of the air flowing through the one of the tunnel tubes as it exits from the one of the tubes into the other one of the tubes.
 3. In a subway system, as set forth in claim 1, including controllably admitting the air from the one of the tubes in front of the train into the cross-connection.
 4. In a subway system, as set forth in claim 3, characterized therein by controlling the flow of the air from the one of the tunnel tubes into the other one of the tunnel tubes by variably regulating the amount of air withdrawn from the one of the tunnel tubes.
 5. In a subway system, as set forth in claim 1, including ventilating the tunnel tubes at a location intermediate the cross-connections by withdrawing air from the tubes and supplying fresh air from the outside atmosphere into the tunnel tubes.
 6. In a subway system, as set forth in claim 5, wherein the ventilating of the air in the tunnel tubes is effected by renewing 40 percent of the air.
 7. In a subway system having two one-way tunnel tubes extending between adjacent stations, wherein the improvement comprises a ventilating system comprising means forming at least one cross-connection between the tunnel tubes at locations adjacent each of the stations, and means located in said cross-connections for withdrawing air from one of the tunnel tubes and directing it into the other one of the tunnel tubes so that the circulation of air can be effected in a closed circuit through the tunnel tubes and the cross-connections whereby the circulating flow of air to the tunnel tubes and the cross-connections avoid drawing air in from the outside atmosphere and causing the flow of air to the stations and through the entrances and exits to the stations.
 8. In a subway system, as set forth in claim 7, wherein means for ventilating the tunnel tubes are located intermediate the cross-connections adjacent the stations and are connected to the outside atmosphere for exhausting air from and supplying fresh air to the tunnel tubes.
 9. In a subway system, as set forth in claim 8, wherein said means for ventilating the tunnel tubes includes fans for withdrawing air from the tunnel tubes and fans for supplying air into the tunnel tubes.
 10. In a subway system, as set forth in claim 9, wherein said means for ventilating the tunnel tubes includes walls forming a ventilation shaft extending between said tunnel tubes and the outside atmosphere, partitions dividing said shaft into a pair of flow passageways for each of said tunnel tubes, each of said flow passageways containing one of said fans so that for each pair of said flow passageways one flow passageway supplies air into one of the tunnel tubes and the other withdraws air from the one of the tunnel tubes.
 11. In a subway system, as set forth in claim 10, wherein said ventilating shaft is located in a middle section of said tunnel tubes between the opposite ends thereof.
 12. In a subway system, as set forth in claim 10, wherein said ventilating shaft is located in the zone intermediate the ends of said tunnel tubes representing 70 percent of the length between the ends of said tunnel tubes.
 13. In a subway system, as set forth in claim 10, wherein said ventilating shaft includes filters for the air being circulated therethrough, sound dampers located in the upper portion of said flow passageways of said shaft, and openable and closeable register members located in said flow passageways for regulating the flow of air into and out of said tunnel tubes.
 14. In a subway system, as set forth in claim 7, wherein said means forming cross-connections comprises at least one conduit forming member extending between the tunnel tubes.
 15. In a subway system, as set forth in claim 14, wherein said conduit forming member includes an injection nozzle for injecting air into the other one of the tunnel tubes after it has been withdrawn from the one of the tunnel tubes.
 16. In a subway system as set forth in claim 7,, wherein said means for withdrawing air comprises fans positioned within said cross-connection.
 17. In a subway system, as set forth in claim 16, wherein said fans are variably operable for regulating the flow of air withdrawn from the one of the tunnel tubes and for supplying the air into the other one of the tubes. 